All Senate

Top Democrats in Colorado this week managed to keep two antifracking measures off the ballot – initiatives that could have caused Sen. Mark Udall (D) all sorts of difficulty in his tight reelection bid.

Businessman David Perdue won Tuesday's GOP Senate primary in Georgia, defeating US Rep. John Kingston. Georgia is a red state, but rise of minorities, who tend to vote Democratic, gives Michelle Nunn a better-than-usual chance.

Calling unmarried women an undermobilized electorate, Democracy Corps touts a populist message to close the gap against Republicans in 12 Senate battleground states, most of them traditionally conservative.

In Tuesday's runoff, voters decide which Republican candidate goes up against Democrat Michelle Nunn, who has polled well in the Georgia Senate race. A US congressman leads a businessman in the race to take her on.

The Mississippi Republican primary between Sen. Thad Cochran and tea party-backed Chris McDaniel has been ugly and could get worse. Ted Cruz is jumping in, and McDaniel is moving toward a legal challenge.

Tea party challenger Chris McDaniel and his supporters are refusing to acknowledge that they lost a Mississippi Republican primary runoff to Sen. Thad Cochran, meaning an already-weird race is getting weirder by the day.

Sen. Thad Cochran could not have won the Mississippi Republican primary without thousands of black voters, mostly Democrats, in an open primary. Opponent Chris McDaniel is steamed, but others may learn a lesson.

Sen. Thad Cochran (R) of Mississippi prevailed Tuesday in the GOP primary against tea party challenger Chris McDaniel. He pulled off the upset with help from black Democratic voters and GOP establishment figures.

Sen. Thad Cochran is facing a tight runoff Tuesday in the Republican primary with the tea party-backed Chris McDaniel. Looking for an edge, he's appealing to African-American voters. It's a tactic that has raised eyebrows.

Political newcomer David Perdue was top vote-getter in Tuesday's GOP primary for the US Senate seat in Georgia. Neither he nor Rep. Jack Kingston, who also advances to the July 22 runoff, is an insurgent Republican.

In a handful of states, including Georgia, Democratic Senate candidates are counting on black voters to turn out big time to help them win. But signs are that enthusiasm for Democrats has been slipping among African-Americans.